I've read many of these before, but I'd like to read them again with discussion and focus. The following is the order I'm thinking of, but I could imagine switching it up.
1. The Prose and Poetic Eddas (Icelandic sagas)
2. The Kalevala (Finnish myths)
3. The Silmarillion
4. Splintered Light and Interrupted Music by Verlyn Flieger
5. Beowulf (Tolkien translation)
6. Sir Gawain and the Green Knight (Tolkien translation)
7. The Tolkien Reader: Farmer Giles of Ham, The Adventures of Tom Bombadil, etc.
8. The Hobbit
9. The Lord of the Rings
10. The Road to Middle Earth by Tom Shippey
12. Songs and Poems: Bilbo's Last Song, The Road Goes Ever On etc.
13. The History of Middle Earth
14. The Children of Hurin
15. The Legend of Sigurd and Gudrun
I'm sure there are many more critical works that should be added, including some of Tolkien's own critical works. I also have not included all of Tolkien's oeuvre, such as the Unfinished Tales, which echo parts of The Silmarillion, History of Middle Earth, and Children of Hurin. In fact, it might make some sense to read versions of the same stories together rather than each book separately (therefore, some of the reads would be simultaneous rather than sequential).
Obviously, I have put a lot of thought into this, so someone, take me up on it!